This invention relates generally to pipe couplers and, more specifically, to a universal pipe coupler and a method of forming a fluid-tight pressure seal with pipes under either high or low pressure or pipes that are made of different materials.
Pipe couplers are known in the art and generally comprise members that are fastened to the ends of two pipes to hold the two pipes in an end-to-end relationship. One type of pipe coupler uses members with teeth to bitingly engage the exterior of the pipe, the members are then pulled toward each other to hold the pipes in an end-to-end relationship. Another type of coupler requires forming an annular groove near the end of each pipe and then placing a flanged member into the groove. The flanged members are then pulled together to bring the pipes into an end-to-end relationship. Generally, the ends of the pipes are sealed with a gasket. Both of these type of prior art couplers utilizes a surface destructive action which disrupts the integrity of the pipe and can weaken the pipe by increasing the stress forces on the pipe or reducing the thickness of the pipe which creates weaker areas in the pipe that could fail. One mode of the present invention provides an improved universal pipe coupler and method of forming pipes into an end-to-end sealing relationship without disrupting the integrity of the pipe.
While preventing disruption of the integrity of the pipes is important for certain pipes, there are other instances where the internal fluid pressure of the coupled pipes and the materials of the coupled pipes are more significant factors. For example, in certain cases high pressure pipe couplers are needed to withstand internal pipe pressures in excess of 1000 p.s.i. In still other applications pipe couplers are needed to couple pipes that encounter only a few p.s.i. The present invention provides a universal pipe coupler suitable for use with either high or low pipe pressures as well as intermediate pipe pressures. In one embodiment of the invention the universal coupler aligns the pipes in an end-to-end relationship while being retained by a collar suitable to the required connection conditions. For example, if the internal pipe pressures are high one can use a collar that is fixedly secured to the exterior of a pipe. If the internal pipe pressures are low one can use a resilient collar for compressively engaging a pipe to frictionally hold the pipes in a coupled condition. If the pipe pressures are in an intermediate range a third collar having teeth thereon, which are normally in non-engagement with the exterior pipe surface until the coupler is engaged can be used. In the latter embodiment the universal pipe coupler causes the collar with teeth to bitingly engage the pipe to thereby enable the pipe coupler to withstand high internal pressures. Thus, knowing the operating pressure range of the pipes allows one to use the universal coupler in combination with an appropriate pipe collar to provide an end-to-end sealing relationship for any of number or different pressure conditions without having to use a specialized pipe coupler.
Another difficulty encountered in coupling pipes is that often times pipes made from different materials need to be coupled together. For example, a plastic PVC pipe or polyethylene pipe oftentimes needs to be couple to a metal pipe. Generally, special couplers are required for coupling pipes made from different materials. The present invention provides a universal pipe coupler for use in coupling pipes made from different materials by allowing a user to couple pipes of different materials by selecting an appropriate retaining collars for each of the coupled pipes.
A further difficulty with coupling pipes in an end-to-end relationship is that the sometimes the pipes become misaligned making the coupling prone to leakage. In the present embodiment the universal coupler includes two alignment surfaces on each coupling member for one pipe and two different alignment surfaces on the same coupling member for the second pipe with each of the alignment surfaces in alignment with each other to thereby ensure that when the two pipe ends are secured therein the pipes are in alignment with each other.
Thus the universal coupler of the present invention allows a user to couple pipes of different materials as well as pipes that support low, intermediate or high-pressure fluids.
U.S. Pat. No. 4,611,839 shows a segmented pipe coupling member that includes inclined end faces.
U.S. Pat. No. 4,461,498 shows a coupling member that uses either a grooved pipe or a member that bites into the exterior surface of the pipe.
U.S. Pat. No. 4,838,582 shows a flexible expansion coupling with an annular sealing member.
U.S. Pat. No. 4,552,434 discloses a multiple keyed pipe coupling that includes grooves in the exterior surface of the pipe.
U.S. Pat. No. 5,813,705 discloses snap action pipe coupler that uses a grove cut in the exterior surface of the pipe.
U.S. Pat. No. 5,578,900 discloses snap action pipe coupler that uses a groove cut in the exterior surface of the pipe.
U.S. Pat. No. 4,471,979 discloses a thin walled pipe with radial projection formed therein for engaging a coupling member.
U.S. Pat. No. 4,702,499 discloses a hinged pipe coupler that applies radial pressure to the pipe.
U.S. Pat. No. 4,886,304 discloses a coupling member with wedging members for engaging the pipe.
U.S. Pat. No. 5,476,292 shows a pipe coupling with compression member for gripping the exterior of the pipe.
U.S. Pat. No. 4,561,678 shows a pipe coupling segment that fits into a circumferential groove on the each of the pipes.
Briefly, the invention comprises a method of connecting pipes in a fluid-tight end-to-end relationship and a universal pipe coupler that in one embodiment includes a non-disruptive pipe collar that maintains the integrity of the pipe ends as the coupler simultaneously aligns the pipe ends and draws the pipe ends into a sealing relationship with a circumferential seal that provides a fluid-tight pressure seal around the pipe ends and in other embodiments maintains the pipes in an end-to-end sealing relationship with either frictional collars, contractable collars or both.